Justification:
Although the distribution area of this subspecies is small (Yaku Island, 505 km²), a survey conducted in 1991 and 1992 (Yoshihiro et al. 1998) estimated 131 troops containing 2,000-3,850 individuals in a coastal area of 12.7 km², and the total population size is considered to be large. Major threatening factors are decrease of deciduous evergreen forests (their main habitat) and increase of coniferous plantations, and annual control kill of over 500 individuals to prevent agricultural crop damage, however, no indication of population decline has been observed at present.